Nozzle diaphragm having cast-in nozzle partitions and method of manufacturing the same



J. H. DORAN v NOZZLE DIAPHRAGM HAVING CAST-IN NOZZLE PARTITIONS AND METHOD OF MANUFACTURING THE SAME Filed May 9, 1922 V. w e m r n 0 c v .UD 0 n ,t t v n n|n m I o H m MA J m w Fig.2. I j: III%IIIII llllll Patented Jan. 13, 1925.

tszaeas UNITED STATES PATENT orrice.

JOHN H. DO'RAN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

NOZZLE DIAPHRAGM HAVING CAST-IN NOZZLE PARTITIONS AND METHOD OF MANU- Y r c EAOTURING THE SAME.

Application filed May 9,

diaphragms forelastic fluid turbines, especially nozzle diaphragms of the type in which the'nozzle partitions are cast into the diaphragms, and has for its object to provide an improved structure of diaphragm and an improved method of manufacturing the same.

For a consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto.

In the drawing, Fig. l is a side elevation of a diaphragm structure embodying my invention, and Fig. 2 is a radial sectional view thereof Diaphragms are usually made in upper and lower halves for purposes of assembling, and in the drawing I have illustrated a half diaphragm. It will be understood,

however, that my invention may be carried out in connection with diaphragms cast in halves or as a whole.

Both cast steel and cast iron have been used in the manufacture of diaphragms having cast-in nozzles. Cast steel is particularly satisfactory so far as strength of the material is concerned but it offers difliculties in that during the casting it is quickly chilled by the nozzle partitions and does not make a good joint with them. In other words, it is difficult to cast the nozzle into steel. On the other hand, nozzle partitions are easily cast into cast iron, but this material is not so satisfactory as steel because it is not so strong. The greatest stresses in a diaphragm occur in the vicinity of the hub and the use of cast iron requires rather thick, heavy diaphragms in order to give the necessary strength to the diaphragms.

Now, according to my invention, I construct a diaphragm in which the outer or .ward from the nozzle 1922. Serial N0; 559,680.

peripheral portion which holds the nozzle partitions is made of cast iron and the inner or web portion is made of cast steel, the two parts being joined together by an interlocking joint which may be somewhat of the nature ofa tongue and groove connection. In carrying out my invention I form the mold for casting the diaphragm in any usual or desired manner, mounting the nozzle partitions therein in the customary way. Then at a point spaced radially in partitions I arrange in the mold a separator formed of a strip of suitable metal reversely bent on itself to form deep corrugations or pockets into which the molten iron and molten steel can flow In the drawing, 5 indicates the nozzle partitions, 6 the cast iron part of the diaphragm, 7 the cast steel part of the diaphragm, and 8 the separator bent-to provide pockets 9 and 10, which receive iron and steel respectively. The separator is made of suitable width so it is supported in the sand of the mold and after the diaphragm is cast the edges projecting beyond the surfaces of the diaphragm are removed. The iron and steel parts of the diaphragm are poured preferably at the same time or about the same time so that they both cool and harden simultaneously. On account of the difference in pouring temperatures of steel and iron, steel being poured at a higher temperature than iron, the steel may be poured first, and after it has cooled a predetermined amount, the iron poured. Upon hardening the iron and steel parts of the diaphragm are firmly joined together.

Vhile I have particularly described my invention as relating to nozzle diaphragms and its use with the metals steel and iron, it will be understood that my invention in its broader aspects is not necessarily limited to this particular use, but may be utilized whenever found applicable and with such metals as desired.

lNhat I claim as new and desire to secure by Letters Patent of the United States. 1s:-

1. A nozzle diaphragm for a turbine having its peripheral portion formed of cast iron and its web portion of cast steel.

2,. A nozzle diaphragm for a turbine having'the part which holds the nozzle partition formed of cast iron and the remainder of cast'steel.

3. Anozzleidiaphragmwfoiwa.turbinehaving its radially outer portion 7 formed of one metal .and .its radially inner portions -formed of a difierentmetahsaid portions being joined by an interlocking joint.

a. A nozzlediaphragm for a turbine hav ing its radially outer portion formediof one metal and its radially inner portion formed of a different metal, said portions being joined by a tongue and groove connection. .5. Themethotl of'manufacturinganozzle diaphragm having its peripheral portion formed. zfrom one ,metal' and its web portion from another :metal, which comprises .arrangingwthe nozzle partitions and a separator in a moldand then pouring the two metals which are to form the diaphragm.

6. Themethod of manutacturing'a nozzle diaphragm having its peripheral portion formed from one metal and its web portion from another metal, which comprises arranging the nozzle partitions and a deeply corrugated separator in a mold and then pouring the two metalswhich are to 'form the diaphragm i v 7 Acomposite structure cast from metals .andhaving one'portion cast from one metal and another portion cast from. another metal, the two portions being joined by a tongue and groove connection comprising a strip whichtis reve-rsely bent .on itsel-t -to provide{oppositely-facing pockets which are filled with the respective metals.

8; The method of manufacturing a cast 1 JOHN DURAN; 

